This invention generally relates to surgical tools, methods, and systems for stabilizing, retracting, and/or inhibiting physiological movement of tissues. In a particular embodiment, the invention provides a robotic surgical stabilizer for use during robotic surgical treatments on a beating heart.
Coronary artery disease remains the leading cause of morbidity and mortality in western societies. A number of approaches have been developed for treating coronary artery disease. While lifestyle changes, endovascular approaches (such as balloon angioplasty, atherectomy, and the like) and/or pharmaceutical treatments are often effective, in many cases it is necessary to resort to surgical procedures such as coronary artery bypass grafting to effectively treat coronary artery disease.
Coronary artery bypass grafting procedures are commonly performed using open-heart techniques. These open procedures generally involve dividing the patient""s sternum and spreading the chest to provide access to the heart. The patient is placed on a heart/lung machine, which oxygenates the patient""s blood and pumps it through the circulatory system during the surgical procedure. After the patient is on cardiopulmonary bypass, drugs are administered to temporarily stop the patient""s heart (cardioplegia) to allow the grafting procedure to be performed. Typically, a source of arterial blood is connected to a coronary artery downstream from an occlusion, thereby bypassing the occlusion. The source of blood may include the left or right internal mammary artery.
While very effective in many cases, the use of open-heart surgery to perform coronary artery bypass grafting is highly traumatic to the patient. Thus, minimally invasive medical technique for performing cardiac surgeries have recently been proposed. These minimally invasive techniques are generally aimed at reducing the amount of extraneous tissue which is damaged during diagnostic or surgical procedures. This can effectively reduce the patient""s recovery time, discomfort, and other deleterious side effects of cardiac surgery. Others have proposed techniques and devices for performing open surgery on a heart while the heart is beating. These proposals generally involve stabilizing a region of the heart by engaging the heart with a tool called a stabilizer. Unfortunately, the proposed techniques for both minimally invasive cardiac surgery and beating-heart cardiac surgery significantly increase the difficulty of these already complex surgical procedures. Formation of the anastomosis (the connection between the arterial source and the occluded artery) is quite challenging in a standard coronary artery bypass grafting procedure when the heart tissues are immobile and exposed for direct manipulation. Even skilled surgeons may find it awkward and/or time consuming to instead perform such procedure in a minimally invasive manner or while the heart is beating.
In robotically assisted surgery, the surgeon typically operates one or more master controllers to remotely control the motion of surgical instruments at the surgical site. The controller may be separated from patient by a significant distance (for example, across the operating room, in a different room, or in a completely different building than the patient). Alternatively, the surgeon""s work station with the controllers may be positioned quite near the patient in the operating room. Regardless, the controller will typically include one or more hand input devices, such as a joystick, exo-skeletal gloves, or the like.
The hand input devices of the surgeon""s workstation are generally coupled to the surgical instrument by a servomechanism. More specifically, servomotors move a manipulator, or xe2x80x9cslavexe2x80x9d supporting the surgical instrument based on the surgeon""s manipulation of the hand input devices.
During a robotic surgical operation, a surgeon using a robotic surgical system may employ, via the manipulator, a variety of surgical instruments, such as tissue graspers, needle drivers, electrosurgical cautery probes, and the like. Each of these structures perform functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting, cauterizing, and/or coagulating tissue, and the like. The surgeon and/or an assistant will mount robotic surgical instruments having suitable end effectors to the manipulator, and will often pass the end effectors through cannula sleeves to an internal surgical site, so as to treat the targeted tissues while minimizing injury to the adjacent tissue structures.
In light of the above it would be desirable to provide improved medical devices, systems, and methods. It would be particularly desirable if these improved techniques facilitated coronary artery bypass grafting and other therapies for tissues which undergo physiological movement. It would further be beneficial to provide robotic tools and robotic surgical techniques for treatment of these tissues so as to take advantage of the recently proposed automated systems to improve the ease and speed with which complex surgeries might be performed, while minimizing the deleterious side effects associated with accessing and/or temporarily inhibiting the motion of the target tissues.
The present invention provides surgical methods and devices which allow closed-chest surgery to be performed on a heart of a patient while the heart is beating. A region of the heart is often stabilized by engaging a surface of the heart with a stabilizer. The stabilizer can inhibit (i.e., substantially reduce) physiological motion of the stabilized region without having to stop the heart. While the stabilized region will not necessarily be absolutely still, motion of the target tissues can be inhibited sufficiently to treat the target tissues, particularly with robotic surgical tools which move in response to inputs of a robotic system operator. A stabilizing surface of the stabilizer will often be coupled to a drive system to position the surface from outside the patient, preferably by actuators of the robotic servomechanism, although manual manipulation from outside the body to position the stabilizer is also possible. Exemplary stabilizers include one or more sutures or other flexible and/or elastic tension members spanning between a pair of jointed bodies, thereby allowing the member to occlude a coronary blood vessel and/or help stabilize the target region between a pair of separated stabilizing surfaces.
In a first aspect, the invention provides a tissue stabilizer for use with a robotic surgical system to treat a target tissue within a patient body. The robotic surgical system has a plurality of manipulators with actuators for moving surgical end effectors in response to inputs by a system operator into an input device. The tissue stabilizer comprises a shaft having a proximal end and a distal end. A first stabilizer body has a stabilizing surface adapted to engage and inhibit movement of the target tissue. A joint couples the distal end of the shaft to the stabilizer, and a drive system is drivingly coupled to the joint so that the stabilizer body can be moved relative to the shaft from outside the patient body. The drive system may allow the stabilizer surface to be positioned using the actuators of a manipulator.
The drive system may be remotely controlled with master controls manipulated by the surgeon or with a manual control outside the body and manipulated by a surgeon""s assistant at the patient""s side. Preferably, a wrist assembly couples the stabilizer body to the shaft so as to provide first and second degrees of freedom, with the degrees of freedom often being about perpendicular lateral pivotal axes. An exemplary stabilizer includes first and second stabilizer bodies coupled together at a joint so that first and second stabilizing surfaces preferably remain substantially aligned when the bodies are moved relative to each other by the actuators of the manipulator supporting the proximal end of the shaft.
In another aspect, the invention provides a surgical stabilizer for inhibiting motion of a tissue at a surgical site. A surface bordering the tissue is accessible at a surgical site. The system comprises a first body having a first anchor and a first stabilizing surface adapted to engage the tissue surface to inhibit motion of the tissue. A second body has a second anchor and a second stabilizing surface adapted to engage the tissue surface to inhibit motion of the tissue. The second body is moveable relative to the first body.
A flexible tension member can be attached to the first anchor and to the second anchor to engage the tissue between the first and second stabilizing surfaces. Optionally, movement of the first anchor away from the second anchor tensions the flexible member and can urge the flexible member against a tissue. Alternatively, the two anchors can be positioned relative to one another and then a flexible and/or elastic member can be positioned around the vessel to be occluded and attached to the already positioned anchors. This allows the flexible and/or elastic member to, for example, occlude and isolate a region of a blood vessel between the stabilizer bodies. By including a pair of anchors on each body, the target region of a blood vessel may be isolated from both upstream and downstream blood flow, greatly facilitating performing an anastomosis during a coronary artery bypass grafting procedure, or the like.
In yet another aspect, the invention provides a surgical stabilizer for inhibiting motion of a cardiac tissue accessed via a minimally invasive aperture, wherein a heart surface borders the cardiac tissue. The stabilizer comprises a shaft having a proximal and a distal end. A first elongate body extends from the distal end of the shaft. The first body has a first stabilizing surface adapted to engage the heart surface to inhibit motion of the cardiac tissue. A width extends across the stabilizing surface, and the body has a thickness less than the width, with at least one lateral bend along its length. A second elongate body is pivotally coupled to the first body at a joint adjacent the distal end of the shaft. The second body has a second stabilizing surface adapted to engage the heart surface to inhibit motion of the cardiac tissue. A width extends across the second stabilizing surface, with the thickness again being less than the width. The second elongate body also has at least one lateral bend, so that the bodies cross distally of the joint and along the stabilizing surfaces when the bodies are in a small profile configuration suitable for insertion through the minimally invasive opening.
The bodies may each comprise one or more anchors for anchoring flexible occluding members and may be of different lengths to facilitate occupying the small profile even with the anchors as part of the bodies.
In a method aspect, the invention provides a method for performing a surgical procedure at a target region of a coronary vessel on a beating heart. The method comprises stabilizing a region of the heart by engaging first and second bodies against the heart with the region disposed therebetween. The target region of the coronary vessel is isolated with a flexible member extending laterally across the vessel from the first body to the second body. Upstream and downstream isolation of the target region may optionally be provided by including two flexible members spanning between the bodies, with the members optionally defined by a single continuous suture loop, tape, silastic tubing, or the like, although two or more pieces of such flexible material may also be used.
In another method aspect, the invention provides a method for performing a surgical procedure on a target region of a beating heart. The method comprises introducing a stabilizer through a body wall. Motion of the target region is inhibited by engaging the heart with a stabilizing surface of the stabilizer. An end effector of a robotic surgical tool is also introduced through the body wall. The target region of the heart is treated with the end effector while the heart is beating, and while motion of the target region is inhibited by the stabilizer.